Improvement in electric clocks



2 Sheets-FShem I. F. .l. BITGHIE.

Electric Blocks. No. 143,847. Patentedr0ct.21, 1873.

2Sheets -Sheet2. F. J. RITCHIE. Electric Clocks.

No. 143,847. Patented0ct.Z1,1873.-

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PATENT OFFICE.

FREDERICK J. RITCHIE, OF EDINBURGH, SCOTLAND.

IMPROVEMENT IN ELECTRIC CLOCKS.

Specification forming part of Letters Patent No. 143,847, dated October21, 1873; application filed October 8, 1872.

To all whom it may concern:

Be it known that I, Fnnnnnrcx Jnnns RITCHIE, of the city of Edinburgh,Kingdom of Scotland, watch and clock maker, have invented certainImprovements in Sympathetic Clocks, of which the following is aspecification:

Currents of electricity have long been transmitted at regular intervals,governed by a standard or regulator clock, through wire cominunicatingwith clock-work at one or more distant points, by which the time isshown. The arrangement causes all the clocks to show the same time, andthe time is more or less perfect, according to the perfection of thestandard or regulator clock at the center. The clocks which are thusoperated or controlled by the currents transmitted may be designatedcompanion clocks or sympathetic clocks. I will use these terms in thisspecification.

There are two distinct systems on which such clocks are operated. In onethe works are turned by a weight or other driving power maintained ineach separately, and which requires periodical winding. Under suchsystem the function of the electrical force transmitted is to regulatethe motion. It may restrain or urge forward the motion, which wouldotherwise be approximately correct. In the other the works of thesympathetic clocks are propelled by the direct force of the electro-magnet operated by the electrical pulsation.

My invention relates to this latter class. It is also of the class inwhich the force is re ceived on pendulums in the several sympatheticclocks. The several pendulums being adjusted to swing in approximatelycorrect time,but a little too slow, the impulses received from thestandard or regulator clock urges forward the motion. The force isexercised in such a way as to maintain the beats of the pendulum andshorten its time of vibration by sufficient increments, according to thecircumstances, to compel an exact conformity with the true standard clocI employ means of communicating motion to the sympathetic clock, and bywhich, in consequence of the small battery-power requisitc to sustainthe motion of the pendulum, the liability of derangement is small. Thisis shown by means of Figures 1 and 2 on Sheet 1 of the accompanyingdrawings.

A is the pendulum of the master clock or standard clock, which may beassumed to be driven in the usual manner by very perfect clockwork, andof course requires periodical winding up. B and G are insulated slendersprings, so placed that the rod of the pendulum A comes in contactalternately with each. D and E are batteries, represented as just belowthe pendulum, but which may in practice be placed in any convenientposition. The positive terminal d of the battery D is connected with thespring B, and the negative terminal 6 of the battery E is connected withthe spring 0. The other terminals of each battery d and e are connectedtogether and to the earth.

F in Fi 1 is a front view, and F in Fi 2 is a side view, of the pendulumof one of the sympathetic clocks or sets of clock-work. The pendulumcarries a coil of insulated copper wire, one end of which terminates ina spring, f and the other in the corresponding spring, f These twosprings, mounted side by side, suspend the pendulum. They are bothinsulated from the fixed suspension-piecef and are insulated from eachother, except by the communication through the coil I. A wire, aconnects the spring f with the terminal screw a of the standard pendulumA, and through it with its pendulum-rod. Another wire, a leads from thespring f 2 to the earth. G and G are permanent magnets, combinedtogether, as shown, and curved to correspond to the motion of the coil Fwhich turns on the center of suspension above, and loosely incloseswithout touching them. The similar poles of these magnetsare placedtogether, so that they act in unison as a single powerful permanentmagnet, with the coil I" adjusted to vibrate freely over them.

The action may be thus explained: WVhen the master pendulum A oscillatesto the left, it comes in contactwith the spring B, and sets in motion apositive current from the pole d of the battery D, through the coil F ina direction to cause an attraction between the lat ter and the left-handpole G of the permanent magnet, causing also a repulsion from the rightpole G. Supposing the pendulum to be already in motion, this conditionfavors its motionto thelel't, and piicl-iens its motion in thatdirection. The train by which this motion is communicated willbcapparent from the drawings. The current flows upward from the batterythrough the wired thence downward through the spring 1 into thependulum-rod A; thence upward through 1ts suspensionsl g', and outwardthrough Its screw-cap (d; or, thence through the wire a" and screw j,down through the springf, and thence through the'coil F where it inducesthe magnetlsm; from thence it flows upward again through the spring fout through the screw j", and down through the wire a mto the earth. Atthe proper time, the normal or master pendulum A returns, and breakscontact from he spring 13, causing its mfiuence to cease upon the coil Alittle later the normal pendulum A has moved suthciently to the right tocome in contact with the spring G, when an opposite condition is inducedin the coil F by a negative current being transmitted troin the batteryE through the same series of connections as were before employed. Thislatter condition induces a tendency in the coil F to swing to the right,and thus, the tendency to swing in. the opposite directions beingchanged at the proper moment, by the action ot the normal or masterpendulum A, the several sympathetic clock-works are maintained at theproper rate of motion.

It may not be necessary to explain that, in the battery E, therespective poles are so arranged that the current through the wire c isin the opposite direction, or electricity ot' the opposite kind, to thatin the wire (1 The contact of the pendulum A with the wire 0 induces amotion, in common hinguage, upward throu gl 1 the tcrmii ialwirewidownthrough the springil thence through the coil F in an oppositedirection. to that betore nduced, and thence all the way in the oppositedirection to that induced by the contact with the spring I The alternatecurrents of positive and negative electricity, induced at regularmtervalsdiy the action of the normal clock, give motion to any number ofsubsidiary or sympathetic pendulums, the number, of course, dependingsomewhat on the power ot the orig inal batteries. Any number withinproper limits mav thus be caused to vibratein unison with. eacli otherand with a regulator-ch)ck. Only a slight battery-power is required,inasmuch as the magnetic influence of the current is applied to theextreme end of the pendulum, where the most powerful efi'ect isproduced. From the momentum of the pendulum the currents may beintermittcd for several seconds without causin its motion to cease. Thepresence of the pendulum in each of the systems of svmpatheticclock-work thus serves important functions, both as a means of receivingthe impulses favorably, and as aregulating and steadying element of themechanism. It is persistent to maintain an approximately true motionunder all conditions, yet subJect to the action of the magnetic impulsesto control it.

Instead ol. the wire coil being attached to the pendulum-rod ot' thesubsidiary pendulum and the magnets fixed to the clock-case, the coil orcoils may be fixed and the magnets carried on the pendulum, as in Fig.5, Sheet- 1, where H are the magnetic bars carried on the pendulum, andI I are fixed coils, into which the poles of the magnets enter. One endof the wirein one coil is connected to one end of the wire in the othercoil, and the other ends are led, one to the screw ot' the normalpendulum, and the other to the earth. Instead oi. magnetic bars H, smallcoils of wire, rendered magnetic by the passing of a current, may besubstituted.

I propose to use a. pendulum loaded above its center of suspension, soas to beat approximately with. the normal pendulum when it is desirableto have corresponding beats, but where, from want of room, this cannotbe conveniently obtained by a pendulum of the same length. For thispurpose I use a coil or coils of wire or magnetic bars below, and thesame above, the point of suspension, working into or around magnets orcoils fixed in the casing, as represented in drawings, Figs. l and 5,which are, respectively, a front and side view. 0 and O are coils ofwire, mounted on. a frame, It It It It, and suspended on the fixed piece0 by the springs O and 0 The magnets I and I, having their similar polesin proximity, are placed so that the coils vibrate freely over them. Thecurrents from the normal clock enter, by the spring 0, into the coil 0,thence into the coil and pass on, by the spring 0, to the line-wire. Theaction is closely similar to that in Fig. .l, but somewhat afi'ected bypassing through two coils.

I employ means for propelling a train of wheel-work (which carries thehands) by the oscillations of a pendulum, acting on two arms or palletssuspended on arbors or springs, alternatel y pressing, by force ofgravity or oth erwise, on the teeth of the cscapemcut-wheel. This isrepresented in the drawings, Fig. 6, Sheet 2, and may thus be described:L is the escapement-wheel, carrying the second-hand, and is cut intothirty teeth. on and a are ar bors, carrying pallets ill and X, thepoints or ends of which pallets press, by force of gravity, on the teethof the scape-wheel Ii, causing it to move in the tbrward direction tillstopped by the are formed on each pallet, respectively. On the samearbors m and a are also fixed arms, 'arrying studs m and a to eitherside 01' the pendulum-rod F, so as to be alternately acted on or raisedby oscillations of the pendulum. The wheel L is shown at rest on thepallet M, the end of which presses against the one tooth, 0, while thesucceeding tooth p rests upon the are on the under surface of thepallet. \Yhen the pendulum oscillates in the direction of the arrow thestud a, by force of gravity, follows it, and, after the pallet H hasbeen removed by the action or the pendulum upon the stud m allows thearm carrying the pallet N, by force of gravity,

to move forward the tooth 8, against which it hasbeen pressing, untilthe tooth. t is stopped by the are formed on the upper side of thepallet N. The reverse oscillation of the pendulum operates upon thepallets in the same way, but in the reverse order.

Additional gravity-weights may be added, if necessary, on arms m and asecured to the arbors. Instead of arbors, suspension-springs may besubstituted for the action of gravity in propelling the wheel.

The motion of the second hand is instantaneous, and rests dead on thedivision of the dial; and no force, however great, will cause the wheelto move forward at any time beyond the arc of the pallet on which it isresting. The wheel cannot be turned backward, except by a force greaterthan the weight of the gravity-arms.

For clocks in exposed situations, a simple detent or catch is provided,which, falling into each tooth when advanced. by the pallet, preventsany force from. turning the wheel backward.

In Figs. 4 and 5 the projecting part Q, takes the place of thependulum-rod in Fig. 6 in imparting motion. It may act 011 similar studsm and of attached to the pallets M N.

An important part of my improvement relates to the adaptation of themeans of propulsion described above so as to enable a halfsecond 1endulum to beat seconds. For this purpose I use only one gravity-armhaving a jointed pallet, which presses forward the wheel at everyalternate swing of the pendulum until locked, as before, on the are onthe upper side of the pallet, as shown in Fig. 7, Sheet 2.

T is the scape -wheel carrying the second hand, and is cut into sixtyteeth. The arbor it carries an arm, N, with ajointcd pallet, N, theweight of which is slightly overbalanced by an adjustable poise, N Twostuds, 12 p are placed to limit the play of the pallet. The end of thispallet, pressing against the tooth of the wheel, causes it to moveforward until the succeeding tooth touches and presses the palletagainst the lower stud p, beyond which no force will cause the wheel tomove. Another arbor, m, carries an arm, M, with a small notch, 7a, whichfalls upon the point of a tooth of the wheel, and, until relieved, noforce will cause the wheel to move either backward or forward. When thependulum F oscillates toward the right hand in the direction of thearrow it leaves the notch on M holding the wheel firmly, and then raisesthe arm N (carrying the jointed pallet N out of contact with the wheel.

,When the arc has cleared the tooth of the wheel, the point of thehinged pallet N is raised by the preponderance of the weight N and will,on the return swing of the pendulum, press against the following toothof the wheel in readiness to move it forward as soon as thependulum-rod, acting on the stud m *aises the arm M from the tooth. Thewheel is then carried forward by the weight of the pallet N and itsconnections until locked as before.

Fi 8, Sheet 2, is an enlarged drawing of the hinged pallet N and theadjacent parts.

Another part of my improvement relates to applying the foregoing to avibrating balancewheel instead of and acting in place of a pendulum. Theesca )ement I have invented for this is shown on Fig. 9, Sheet 2. Y is awheel in connection with the train of wheel-work carrying the hands, andis held steady by a very slender spring, 2. X is a roller fixed to thearbor of the balance, and has a jointed pallet, 00, projecting beyondits periphery, which is pressed outward by a slender sprin When thebalance vibrates in the direction of the arrow, the projecting palletcarries forward the tooth of the wheel. The pallet, in returning, clearsthe tooth by the action of the joint, and, being then pressed outward byits spring, is in readiness to carry forward the succeed in g tooth uponthe next vibration of the balance.

In all these diiierent methods it will be seen that it is theoscillations of the pendulum or balance, and not the currents from thenormal or standard clock, which are recorded by the wheel'work, so thatany accidental stopping of the current for even several seconds will notaffect the time shown by the sympathetic clock.

My improvements can all be applied to pen dulums which are of differentlengths from that of the normal clock.

Having explained the way in which my improvements are worked out, I donot claim as new all. that has been described; but

What I claim as my invention is--= 1. The insulated springs B C, withtheir re spective connections (1 0 in combination with master pendulum Aand the connection a a to one or more sympathetic clocks, as hereinspecified.

2. The positive detent M, as constructed with notch 70, in combinationwith ratchetwheel L, pendulum F, and impulse-pawl N, as shown anddescribed.

FRED. J. RITCHIE.

Witnesses:

ANDREW B. STEWART,

Of No. 1 India Buildings,

Edinburgh, Sol c itors 01617:. D. CAMPBELL,

OfN 1 Indie Buildings,

Edinburgh, Solicitofis Clerk.

